1. Technical Field
The present invention relates to a switch device provided with a sliding member that is supported by a switch base plate so that it is able to slide along a predetermined sliding direction, and in which switching operation is carried out according to the position of the sliding member. The present invention also relates to an assembly method of the same.
2. Related Art
Recently, various vehicle seats such as car seats are fitted with seat belt devices for protecting the occupants thereof in the event of an emergency such as an impact. Such types of seat belt devices are provided with a buckle and a tongue plate for latching to this buckle. In such seat belt devices, the seatbelt is fastened by the tongue plate being inserted into the buckle, and by latching the tongue plate with a latch mechanism that has been built into the buckle. Furthermore, the seatbelt is unfastened by releasing the latching state by means of the latching mechanism and removing the tongue plate from the buckle. In such a seat belt device, there is normally a buckle switch provided in the buckle, which detects the latching state with respect to the tongue plate, and, for example, a control portion of the vehicle determines the fastening status of the seat belt using a contact signal output from the buckle switch.
The buckle switch used in the above described seat belt devices is known and has been described in Japanese Patent Application (JP-A) No. 2005-190906. The buckle switch described in JP-A No. 2005-190906 is provided with a base plate (switch base plate) that has a predetermined conductive pattern formed on one of the faces thereof (the sliding surface), and a sliding member that: has claw portions formed on each of the end portions in the width direction thereof, has a slider contact disposed on an opposing face of the switch base plate, the opposing face facing the sliding surface; latches respectively each of the end portions in the width direction of the switch base plate by the pair of claw portions; and thereby is supported by the switch base plate so as to be able to slide in the longitudinal direction of the switch base plate.
Here, the slider contact is formed as a long thin beam shape, and is supported by the sliding member in a cantilevered state. The slider contact is provided with contact portions at the leading end side thereof, the contact portions being curved substantially in a V-shape so as to project out toward the sliding surface side, and these contact portions are pressed against the sliding surface (against the conductive pattern).
In a switch device like the one described in JP-A No. 2005-190906, when the sliding member is being assembled to the switch base plate, after the positioning of the opposing face of the sliding member above the extending face of the sliding surface of the switch base plate while keeping the sliding member to the outside in the longitudinal direction of the switch base plate (sliding direction), the sliding member is slid along the sliding direction relatively toward the switch base plate side, and the switch base plate is inserted between the pair of claw portions of the sliding member. By so doing, both end portions in the width direction of the switch base plate are latched by the pair of claw portions of the sliding member, and the sliding member is supported by the switch base plate so that it is able to slide as well as the sliding member being prevented from separating away from over the switch base plate.
However, when a sliding member is assembled to a switch base plate with such a method, when the switch base plate is being inserted between the pair of claw portions of the sliding member, unless the slider contact, which has been disposed to the sliding member, is pressed and bent by the end portion at the insertion side of the switch base plate (the leading end portion), the switch base plate cannot be inserted between the pair of claw portions without the slider contact getting in the way. However, since the slider contact is formed of a thin metallic plate, there is sometimes deformation (plastic deformation) of the slider contact that originates from the vicinity of the contact portions due to a pressing force from the switch base plate when the leading end portion of the switch base plate has made contact with the contact portions of the slider contact.
Such a problem as described above may be reliably avoided with high probability by adept manipulation by an operative when carrying out assembly of the switch device, however, variation in the dimensional precision of the slider contact and the influence of the level of the operation skill cause such a problem as described above cannot be completely avoided. This makes the checking of the switch devices complicated and results in a decrease in the yield of the switch devices.